Galvanic cell.



.containin it. it. al ies EIGBDUCH L. KAPLAH, OF BRDOZQLYN, NEW Y ORK.

GALVANIG CELL.

messes.

Ito Drawing.

T 0 all whom it may concern:

Be it known that I, Monnuorr L. Keenan, a citizen of the United States, and a resident of Brooklyn, in the county of Kings and State of New Yorkfhave invented certain new and useful Improvements in Galvanic Cells, of which the following is a specification.

The object of the present invention is to provide an economic method of preparing a highly eiticient depolarizer for the galvanic cell of the Le Clanche type, especially for those of the miniature kind, lately come into use in portable lights and pocket lamps. in these kinds of lamps a compact high grade battery capable of yielding steady current is essential, and since steadiness of current is hardly attainable when. powdered pyrolusite is used as a depolarizer, its use has been given up, and in its stead, artificial products such as hydrated manganese peroxid have been introduced. These products contain from to per cent. of M and besides bulkiness have the great disadvantage of being exceedingly costly. This is due to the fact that their use is only possible when ontirely free from basic or acid impurities, otherwise local actions sets in making cells the same of no practical value. Local action due to the presence of basic impurities is the reason Why cheap artificial products such as, Weldon mud and others known as recovered manganese have been found unsuitable for battery manufacture. For the purpose of removing impurities, it has been attempted to treat these substances with dilute acids such as H 50 or HCl, but. though the resulting products have shown some shelf-standing qualities especially after careful washing and dehydration, these proc esses have not been generally adopted for several reasons.

Firstly, these treatments greatly impair the efficiency of the productas a depolarizer; the resulting product, due to losses in oxygen during drying and dehydration, being not very high in MnO Secondly, the treatment With acid removes not only injurious impurities but also considerable quantities of MnO, thus reducing the yields of manganese product considerably.

I have discovered a process free from the above objections, capable of yielding a high grade manganese peroxid highly ellicient as a depola-rizer and is applicable to all manga- Specification of Letters Patent.

Application filed July 11. 1918. Serial .lil'o. 24,439.

nese peroxid compounds contain? impurities or constituents, espr t compounds known as recovered nese.

It consis in mixing these cmupouu'd: with sui'iicient quantitiesoi nitric acid so as to bind all basic substances present, including M110, to the acid. Care should be ta he to apply enough liquid to convert the powderysubstances into an even damp ma s. those cases Where only a small amount of acid is required, water 11 be added [-5-1 as to insure the equal distribution of and tration by the acid. The damp ma s inn obtained is placed in an acid-res or chamber with facilities iterher heated to drive off Water and the canes acid and the temperature then grzuiuall raised to decompose the manganese formed previously. As the decinnpd. point of nearly all nitrates lies much hi than that of manganese nitrate. all. 1 soluble impurities contained originally in the material are now present in the form of? soluble nitrates which are easily remo ed by extraction with Water.

The resulting product, after filtering. drying low temperatures. co: fine, dense. gray-color d powder lt most closely in appea'ancc the pen mineral but is far superior to the la' purit v and etliciency. These prod-.1" having been incorporated. with quantitiesof conducting mate graphite, have been found to Do. ingly high depolarizing powers.

I have found also that in man preferable to introduce the cone rial before the acid trez'itment.

main

possible through the presence oi a coed a more even heating of the mass a local ove1.-heating of the niatrial at lVhat l claim as my invention and desire to secure by Letters-Patent, is:

1. A method of preparing an electrode material for galvanic cells comprising the in corporation with a manganese per-o1. l c pound of a conducting i'naterial. moistc K the powdery mass with a liquid ccntamin sufiicient nitric acid to bind the basic sub-- stances present to the acid, heatin sultant damp powder to drive ot moist and excess of acid, then increasi. t is t perature to decompose the manganese nitrate formed, extracting the residual nitrates with water,.and then filtering and drying the material.

2. A method of preparing an electrode material for galvanic cells comprising the incorporation with a manganese peroxid compound of sufficient nitric acid to bind the basic substances present, including MnO, to the acid,,decomposingthe manganese nitrate formed, and removing the residual nitrates, a conducting material being added to the compound at any convenient stage.

3. A method of preparing an electrode material for galvanic cells comprising the incorporation with a manganese peroxid compound of a conducting material, adding to this product sufiicient nitric acid to bind the basic substances present, including'MnO,

to the'acid, decomposing the manganese nitrate formed, and removing the residual nitrates.

l. A method of 'preparin an electrode material for galvanic cells rom a manganese peroxid compound, which consists in converting the basic substances present in the compound into nitrates, decomposing the manganese nitrate and removing the residual nitrates, a conducting material being added to the compound.

Signed at New York city, in the county of New York and State of New York, this 10th day of July, A. D. 1918.

MORDUCH L. KAPLAN. Witnesses ARTHUR MARION,

CHAS. C. GILL. 

